The conventional sauna device of the convection type employing an electric heater is popular, but it has a disadvantage that electric energy is expensive.
To overcome such disadvantage, convenient and economical sauna devices were developed, wherein liquid or gas fuel is burned. The heat of combustion was converted to infrared rays which radiate the heat to the human body.
The infrared ray radiation device usually employs the burner and other combustion device outside the sauna chamber since it is dangerous to burn fuel in the sauna chamber. The combustion heater devices require broader floor space than sauna device with electrical heat source.
These problems are more serious for smaller scale sauna.
Although sauna devices to overcome the above disadvantages are disclosed in the specifications of Japanese utility model application Nos. 59-162174 and 60-131970, the devices there disclosed require a larger relatively floor space in comparison with an electric type sauna device with conventional electrical heat source.
The conventional infrared ray radiation sauna device does not provide the desired heat efficiency, safety and easeness of maintenance or inspection work.